Method of and apparatus for cold drawing tubes



April 19, 1932. s. D. lNscHo METHOD OF AND APPARATUS FOR COLD DRAWING TUBES Filed June 4, 1930 5 Sheets-Sheet 1 S11/vanto@ April 19, 1932. K s, D. lNsqzl--Ky 1,855,051

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`AprilY 19, 1932.; sfD, MgCl-i0, 1,855,051

METHOD OFy AND APPARATUS FOR GOLD DRAWING TUBES Filed Jun 4, 1930 5 Sheets-Sheet 3 tot dumm,

METHOD OF AND APPARATUS FOR 'COLD DRAWING TUBES v Filed June 4, 1930 5 Sheets-Sheet 4 l-Vl/l.

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April 19, 1932. s. D. lNscHo M 1,855,051

METHOD OF AND APPARATUS FOR COLD DRAWING TUBES Filed June 4, 1930 5 Sheets-Sheet 5 3mm/doc I Patented pr. 19, 1932 l UNITED STATES PATENT oFFlcE SIDNEY DAVID INSCHO, OF SHELBY, OHIO METHOD E AND APPARATUS FOR COLD DRAWING TUBES Application filed .Tune 4, 1930. Serial No. 459,185.

This invention is directed to a method of expanding, and stripping in immediately and apparatus for cold drawing tubes Wheresuccessive sequence without the necessity of in the conventional steps of drawing, expandphysically reversing the tube or substantially ing, and stripping are so synchronized and changing its position, for following the drawcorelated as to materially increase the output ing operation, the drawn tube is in position C5 in a given time, without sacrificing quality to be delivered to the expanding machine, and without increasing labor or power reand following the expanding operation, the quirements. expanded tube is in position to be secured in The conventional steps in cold tube drawthe stripping machine, whereby the time and l" ing, consisting in inserting a mandrel in the labor elements incident to physical transfer- G0 tubular body, drawing such body and manence of the tubes from one machine to another drel through the predetermined die, subjectis entirely avoided. y ing the tube and mandrel to an expanding ma- In addition to the method, the invention A chine to loosen the tube on the mandrel, `and contemplates an apparatus for carrying out i5 finally stripping thedrawn tube from the the method, wherein a single machine con- 65 mandrel, have heretofore required the use of struction includes opposite parallel draw independent and separated machines for benches, which are arranged beyond a cendrawing, expanding, and stripping, 'and the trally disposed expanding machine, with the necessity of attendant labor to transfer the draw heads of the draw benches providedI tube from one machine to the other, with the with means to strip the previously expandedl result that each tube was subjected to the tubes simultaneously with the tube-drawing successive operation as a single element, and Operations of such heads; the machine strucin its transference from one machine to the ture including means for transferring the other, frequently requiring reversal, a time drawn tubes into line with and for easy transloss was occasioned which materially limited ference to the expanding machine, and means 7o the possible output, to say nothing of the inbeyond the expanding machine to transfer creased labor and space required in the incithe expanded tubes into a position permitting dental handling. their ready .connection to the stripping The present method materially increases means. 0 the output by so arranging and corelating the AThe apparatus, more specifically considerso various necessary machines that thesuccesed, includes a single machine unit, the sides sive operations are synchronized, vdispensing vof which are constructed to provide more or substantially with the usual labor requireless conventional draw benches, and between ments and permitting comparatively few opwhich benches there is arranged a convenerators to carry o ut the full operation with a tional expanding machine. The draw heads minimum of time and handling, with the reof the dra7 benches are PlOVided With lateral sult of a materially increased output. clamps and the remote ends of the drawy An important and characteristic step of the benches are also provided with fixed clamps, improved method is the corelation of the the said clamps providing respectively fOr endrawing and stripping operation, wherein gaging the tubes and mandrels in the stripthese operations may be simultaneously perping operation, to cause the operation of the formed; t-he corelation permitting the stripdraw heads in the drawing operation to si `ping of one or'more tubes which have been multaneously strip the tubes from their previously drawn and expanded simultanemandrels of previously drawn and expanded ously with the initial drawing of a tube, thus tubes. The ends of the machine unit beyond currying out the drawing and stripping operthe expanding machine are provided with ations in a single operation. transferring arms, preferably mechanically The met-hodalso materially facilitates the Operated, which at the entrance end of the exhandling of the tubes following any one stage panding machine serve to transfer the drawn of operation, for it provides for drawing, tubes from the draw benchon either side to a mposition in line with and convenient to the expanding machine, while the arms at the exit end of the expanding machine serve to transfer the expanded tubes to a posit'- on convenient to the stripping instrumentaliti'es forming in effect part of the draw bench.

The apparatus not only synchronizes the conventional steps in cold tube drawing, but so corelates the various necessary machines as to insure maximum speed and minimum handling in the various operations,'obvious ly tending to better qualitythrough lack of possible injury through handling together with a materially increased output over conventional methods and apparatus.

The invention in the preferred form of construction is shown in the accompanying drawings, in which Figs. 1 and 1t together constitute a plan vview of the unit construction, including spaced draw benches and an intervening expanding machine, the draw benches having means for stripping the tubes .from the mandrels.

Fig. 2 is an enlarged section on the line 2-2 of Fig. 1a.

The apparatus for carrying out the im 'proved method, consists generally in a more n or less unitary construction includingduplicate spaced draw benches, having as such a somewhat conventional construction and operation; an expanding machine, also substanvtially conventional in construction and operation. arranged between the drawbenches, and serving to expand tubes drawn on both benches; and stripping instrumentalities, supported on the respective draw benches, and for the purposes of this invention coordinated with the drawheads of the draw benches, for the simultaneous drawings and stripping operations.

The construction includes opposed and relatively spaced draw benches, indicated at 1 and 2. The draw benches are of similar con" struction, both yoperating in the same direction, and each involving the familiar elongated 'arrangement 3, removably receiving a conventional die 4 at one end, with a trackway 6 beyondthe die to movably support the draw head. The die, vthough interchangeably mounted, is fixed relative to the bench when in operative position, the die-aperture 7, serving to draw down the exterior of the tube, indi.-

and preferably convention drive mechanism,

not necessary to illustrate.

The draw head 9, as illustrated more particularly in Figs. 6, 7, and 8, includes a base 12, having relatively-rearwardly converging channels 13, to receive gripping jaws 14, for gripping the end of tube during the drawing operation. The jaws are serrated or `otherwiseformed on their proximate faces for good gripping action, and move toward each other in their gripping movement, to there insure that the resistance of the tube will increase the grip of the jaws. .The base is provided with a vlever 15, operated to initially move the jaws 14 into tube gripping relation, and further with an extension 16 in which a hook 17 is pivotally supported. This hook has a lateral projection 18 terminall-y connected to a rod 19, passing through a guide, and provided beyond the same with a spring held between the guide and an adjustably mounted collar on the rod. The spring 20 being thus tensioned, serves to hold the hook in operative position, as will later appear, and at the same time permit sufficient yielding under undue strain to prevent breakage. The hook terminal and lever 15 are normally inoperative, that is with the hook in raised position, free of the chain 11, and the lever moved to permit separation of the jaws 14. In this inoperative position the draw head is free of connection with the chain 11, and is arranged immediately adjacent the die 4.

Each draw head 9 is further provided with I 'means for gripping thetubes, to cause the tubes to move with the dra-w heads in the stripping operation. This detail will be later described in connection with the stripping mechanism.

Arranged between and immediately adjacent the draw benches 1 and 2 is an expending machine 21.` This machine is of any conventional or preferred type, being here indicated as including rolls 22, with angularly-related axes.4 The expanding machine is of course understood to be complete in detail, so that tubes drawn down on the mandrel, as will later appear, may be suffciently expanded relative to the mandrel, to permit stripping of the tube from the mandrel. Thev expanding machine is thus arranged between and closely adjacent the respective draw benches, with the intention of not only facilitating the expanding of tubes drawn on both benches, but for carrying out the method of synchronizing the respective operations.

In line with the inlet end of the expanding machine and between the respective draw benches, is arranged a trough-like support 23, in which the drawn tubes are arranged for delivery to the expanding machine. A somewhat similar trough like support 24 is arranged in line with the expanding machine beyond the exit end of the latter, this latter trough receiving the drawn tubes after expanding. The trough 23 is of V-form in vertical section, and arranged on each side of this trough is ashaft 25. Arms 26 are secured to each shaft,and extend, respectively, toward the opposed draw benches. The arms, of which there may be any desired number in each group, have slightly-upturned free ends 27, and terminate at one side of the adjacent-draw bench. The arms of each group are designed to receive the tubes following the drawing operation on each draw bench, and transfer such tubes to the trough 23 for delivery to the expanding machine. To operate the respectivegroups of arms, each shaft has a lever lixed thereto as 28, the levers being in turn connected to operating devices, as air cylinders 29 or any convenient power the air pressure of which is suitably controlled in any appropriate manner. Thus at will, 'a tube drawn on either bench, may be placed on the arms 26, and following appropriate control of the operation means the free ends of the arms may be i elevated to cause the drawn tube to gravitate into the trough 23, ready for delivery to the expanding machine 21. In order to facilitate the Withdrawal .of the tubes from their supporting jack after stripping, as will be later explained, each arm 26 is hinged adjacent the shaft 25, as at 30, permitting the greater length of the arm toward the free end to be turned up out of the way when desired, as indicated at 31 in Fig. 5.

i Thus through the selective use of the transfer arms 26 of either group, the tubes drawn on either bench may be delivered to the trough 23 for passage through the expanding machine, and as the tube delivery from 3 the respective draw benches may be in succession, or in an order, it is apparent that the expanding is at all times conveniently arranged for a synchronized operation with the tubes from both or either draw bench.

i Transfer' arms are also arranged for co- 3 trough 24', being, however, connected t0 a common shaft 33, mounted adjacent each draw` bench. The free ends' of the arms 3 2 lie normally in vertical divisions of the trough 24, so that the free, slightly upturned ends of 5 the arms, when infnormalvpositions, are in effect art of the lbottom of the trough, and

direct y support the expanded tubes delivered to said trough 24. One of the arms of each group is connected to an air cylinder, or other operator, indicated at 34, the air pressure to which is manually controlled in any appropriate manner, so that at will either group ot' arms 32 may have their free ends elevated, carrying with them the particular l tube in the trough 24, and delivering this tube toward the adjacent draw bench.

Of course it is to be understood that each group of arms- 32 leads from the trough to one ofthe draw-benches, so that an expanded tube may be selectively directed to one or draw bench for the stripping operation, and

this operation, in .its relation to the drawing operation, constitutes one of the important features of the present invention.

As previously stated each draw head 9 is provided with means whereby such draw head may serve during and incidental to the drawmg operation, for stripping the expanded tubes from the mandrels. For this purpose the base 12 of the draw head is laterally extended, preferably toward the expanding machine 21, to provide a clamp plate 35, the upper` surface of which is pro vided with spaced serrated areas 36. A cooperating clamp plate 37, having guide pin connection at 38 with the plate 35, is also provided with serrated areas 39 to register with the areas 36 of the plate 35. Adjusting means, such as a shaft 40, terminally mount-- ed in the plate and having threaded cooperation with the plate 37, and operated through a hand wheel 41, provides for the desired relative operation vof the platesfor clamping or releasing the tubes.

In longitudinal alinement with the grip- A'ping' means described, the bed of the draw bench, or a lateral extension thereof, is provided with cooperating clamp plates, indicated at 42, and suitably formed for receiving and holding the ends of the tube mandrels. l,These latter clamping plates may be' similar tothe clamping plates 35 and 37, except ithat they are in fixed position relative to-the draw bench, and their cooperating clamping surfaces are particulacrly 4formed to receive and grip the ends of the mandrels.

Racks 43 are arranged conveniently adja- 'cent each draw bench to receive the tubes to be drawn, and in the` operation of the improved apparatus for carrying out the novel method of tube treatment, it 1s to be understood that either draw bench may be operated to the exclusion of the other, or both may be operated simultaneously.

In operation, a tube indicated at 44, is lifted from one of the racks 43 and placed on the adjacent draw bench, where one operator inserts a mandrel 45 into the tube, and a second passes the pointed and flattened end of the tube through the die 4, and between the jaws 14 of the draw head 9. The second operator then opera-tes the lever 15 to clamp the jaws 14 on the end of the tube, the draw head at this time being immediately beyond the die. Such second operator then -moves the hook 17 downwardly to cause its hooked end to engage in the lnoving chain 11. The tube and mandrel are thus drawn through thexed die 4, drawing the material of the tube onto the mandrel, as clearly shown in Fig. 3, and as well known in the tube drawing art. Thus the mandrel, which extends the full length and beyond one end of the tube, defines the inner diameter of the tube,

p while the die defines the outer diameter.

When the drawing operation is completed, the drawn tube with its contained mandrel is transferred to the arms 26 adjacent the particular draw bench, and the cooperating air cylinder 29 or any convenient power is operated to raise the free ends of the arms 26, causing the drawn tube to gravitate toward and be delivered into the trough su port 23. Another operator then simp y moves the tube forwardly into the expanding machine 21, where the tube is loosened relative to the mandrel. Following the operation of the expanding machine, the tube is 4'moved longitudinally for a short distance .into the trough support 24, where it rests on the free ends of the arms 32. Either group of arms being operated by the appropriate air cylinder 34, the expanded tube is directed toward the draw bench -and into a position between the clamps, one forming part of the draw head and including the plates 35 and 37 and the other fixed to the base structure, and including the plates 42. The pointed and flattened end of the tube is secured between the plates 35 and 37, and the rojecting end of the mandrel is secured etween the plates 42. Then as the draw head advances for the drawing operation of another tube subsequently secured therein, the clamps for the tube move relatively to the clamps for the mandrel and the tube is stripped from the mandrel simultaneously with and under the same power as employed for the drawing operation.

Of course the above description of the operation has beenthat of a single tube in its passage through the apparatus, during which it was subjected to a drawing, ex-v panding and stripping operation. The continued operation of themachine results in a successive series of tubes in continuous treatment, that is while tubes are being drawn on one or both draw benches, previously drawn tubes are passing through the expanding machine, and previously expanded tubes are being subjected to the stripping operation. Thus for each drawing operation, following a suliicient operation of the apparatus, there will be a tube or tubes ready for stripping, and such tubes will be clamped in position and stripped simultaneously with the drawing operation. This provision for stripping is arranged to accommodate two tubes on each side, and therefore, as it is en'- tirely practical to'operate both draw benches at the same time, the apparatus provides for the simultaneous drawing of at least two tubes and the stripping at the same time and incidental to the drawing operatlon of at least'four tubes.

This simultaneous drawing and stripping is an essential feature of the method and apparatus, and it is to be noted. that the strip.- ping operation takes place so close to the active area of the draw bench, that when the tube has been stripped, vthe withdrawn mandrel is in position to be most conveniently and readily used for insertion in the next tube to be, with such mandrel, subjected to the drawing operation.

Another and important characteristic feature of the method is the synchronization of the various operations, incident largely to the close relation of the operating mecha,

nisms and the particular manner'in which the tubes are delivered from oneto the other: The tubes when drawn are delivered without change in endwise relation to the inlet trough for the expanding machine, and again Without change inA endwise relation delivered from the outlet trough beyond the expanding machine to the stripping means. Thus the tube is passed through the various steps of drawing, expanding, and stripping, without the necessity of reversing the tube, and following only a relatively lateral movement of the tube at the respective ends of the apparatus. Thus the tube is moved in one direction in drawing, and without change moved -in a reverse direction for expanding, and still without change moved a ain in a reverse direction for stripping. he tube and mandrel thus maintains the same relative direction under all operations, is never reversed, and its relative lateral bodil movements from the draw bench to ahnement with the expanding machine, and from beyond the expanding machine to the stripping means, are so nearly equal that the respective operations are or may be more or less exactly timed to insure steady and uniform output.

The tubes 44 when stripped from the manf rra-55,051 5 the expanding of the drawn tubes before stripping, whereby to increase the output and reduce the labor and expense in the operations. Furthermore, the method consists in so synchronizing the respective and necessarily successive operations, as to permit their being carried out in timed sequence, with any one operation being carried out with respect to one tube, while other operations are being carried out with respect to other tubes. The method of operation insures complete drawing, complete expanding, and complete stripping by subjecting the tube following each operation to direct reversal of travel for the succeeding operation, without bodily reversal of the tube and mandrel or the necessity of other than minimum handling of the same.

The apparatus employed reduces to a minimum the operating area required, provides two `opposite draw benches, either or both of which may be operated, and arranges b'etween the draw benches an expanding machine, the corelation permitting the expanding machine to selectively serve either or both draw benches, with the minimum of tube movement, and permits the draw head of the draw benches to serve as stripping means, a convenience largely incidental to the relative close disposition of the expanding machine.

Of course the .invention contemplates the use of conventional machines for the various operations, and is to be in no wise restricted by the detail showing herein.

Having thus described the invention, what is claimed as new, is

1. A unit organization for tube treatment comprising a draw bench, means for moving the tube relative thereto for drawing, an expanding machine, means for moving the tube therethrough in a. directionreverse to the movement of the tube on the draw bench, and stripping means through which the tube is moved in a direction opposite its travel through the expanding machine and in the same direction of travel on the draw bench, whereby the tube may be directed through the successive operations without reversing its position.

2. An apparatus for tube treatment including a unit organization comprising a draw bench including a draw head, an expanding machine located adjacent the draw ench, means for directing the tube through the expanding machine in a direction opposite to the travel of the tube under the in ence of the draw head, and means carried 'by the draw head for connecting a tube thereto for stripping simultaneously with the operation of the draw head for drawing a subsequent tube, the movement of the tube in a similar direction for drawing and stripping and 1n a reverse directionfor expanding 'rogviding for the successive operations wlt out.

reversal of tube position.

3. An apparatus for tube treatment consisting in a unit organization comprising laterally spaced draw benches, stripping means arranged vadjacent said draw benches, an expanding machine arranged between the draw benches, means for transferring tubes from either draw bench laterally and without reversal to a position to cooperate with the expanding machine, and means for transferring vtubes laterally without reversal beyond the expanding machine to either stripping means.

a. An apparatus for tube treatment consisting in a unit organization comprising laterally spaced draw benches, stripping means arranged adjacent said draw benches, an expanding machine arranged between the draw benches, means for transferring tubesvfrom either draw bench laterally and without reversal to a position to cooperate with the expanding machine, and means for transferring tubes laterally without reversal beyond the expanding machineA to either stripping means,

means operative in the use of either draw bench for stripping a tube previously drawn and expanded, ,and means for transferring the tubes from the draw benches for cooperation with the expanding machine without 'reversal of tube position, said tubes in cooperation with` the expanding machine moving in a direction opposite to their movement in the drawing or stripping operation.

7. An apparatus including as a unit organization laterally spaced draw benches each drawing in the same direction, an expanding machine arranged between the draw benches and operating in a direction opposite that of the draw benches, and stripping means arranged beyond the expanding machine and operating in the direction ofthe draw benches, whereby the tube may pass through the successive operations through reversal in direction of movement without reversal .of position. y l

8. An apparatus including as a unit organization laterally spaced draw benches, an linterposed expanding machine, arms for `transferring the drawn tubes from the draw benches tothe expanding machine, stripping ,r''ieans arranged beyond the expanding ma- A chine and adjacent the draw benches, and

arms operative to transfer the expanded tubes to the stripping means, the tubes in the expanding machine moving in a direction opposite their movement during drawing and stripping without reversal of position.

9. An apparatus for tube treatment comprising in a unit organization laterally spaced draw benches, an interposed expanding machine, stripping means arranged adjacent each draw bench, groups of arms associated with each draw bench and arranged in both directions beyond the expanding machine, the groups of arms at one end of the expanding machine serving to direct the drawn tubes from the draw bench to the expanding machine and the groups of arms at the other end of the expanding machine serving to direct the expanded tubes to the stripping means, and means. whereby the respective groups of arms may be selectively operated.

10. A method of tube treatment consisting in drawing a tube, moving the tube laterally and then in a direction opposite the drawing movement and expanding the tube during such opposite travel, then moving the eX- panded tube laterally and into a position for stripping under stripping movement'in the same direction as the previous drawing movement, and stripping the tube.

11. A method of tube treatment consisting in drawing a tube, moving the tube laterally and then in a directionopposite the drawing ymovement and expanding the tube during 4such opposite travel, then moving the expanded tube laterally and into a poslt-ion for stripping under stripping movement'in the same directions as the previous drawing movement, and stripping the tube simultaieously withthe drawing of a lsucceeding tu e.

12. A method of tube treatment consisting in simultaneouslydrawing at least two tubes, moving the tubes toward each other into a common plane, then moving the tubes successively in a direction opposite to their drawing movement and expanding the tubes during such opposite travel, then moving the expanded tubes laterally into the plane of movement of a previous drawing operation, and stripping the tubes so positioned coincidently with the drawing of succeeding tubes.

13. A method of tube treatment consisting in drawing a tube, moving the tube bodily without reversal-into a plane different from the drawing plane, then expanding the tube by movement of the tube in the new plane in a direction opposite to that during drawing movement, then returning the tube substantially into the drawing plane. for stripping operation, and stripping the tube by stripping movement in a plane substantially coincident with the initial-drawing plane.

14. A method of tube treatment consisting `ried out in substantia in drawing, expanding and strippin the tube without reversal of the tube, wit the drawing-and strippin operations being cary the same plane and through movement in the same direction, and the expanding operation being carried out in a different plane and through movement of the tube in a directly opposite direction.

15. The. herein described method loi. tubeV treatment consisting in drawing -at least two tubesl simultaneously in the same direction but in relatively different, laterallly spaced planes of operation, moving the drawn tubes from each drawing plane into a c ommon intermediate plane, moving the tubes in such common intermediate plane successively in a direc-tion opposite to that incident to the drawing operation and expanding the tubes during such opposite travel and then moving the tubes laterallyinto either previous drawing plane for stripping, and strippingl the tubes through operation in the same direction as in drawing movement, with the effect to draw, expand and strip the tubes wit-hout endwise reversal and through movement in two relatively opposite directions in v different planes.

16. The herein described methodof tube vtreatment consisting in drawing atleast two tubes simultaneously in the same direction but in relatively different, laterally spaced planes of operation, moving the drawn tubes from each drawing plane into 4a common intermediate plane, moving the tubes in such common intermediate plane successively in a direction opposite to that incident to the drawing operation and expanding the tubes during such opposite travel and'thenmoving the tubes laterally .into either previous drawing plane for stripping, and stripping the tubes simultaneouslywith the drawing of a succeeding tube through operation in the same direction as in drawing movement, with the effect to draw, expand and strip the tubes without endwise reversal and through movement in'two relatively opposite directions in different planes.

In testimony whereof I affix my si ature.

SIDNEY DAVID INS HO. 

